Adjustable grinding disc



Sept 16, 1958 -A. DITTING ETAL 2,852,203

ADJUSTABLE GRINDING nrsc Filed Nov. s, 1954 ATTORNEYS ADJUSTABLE GRNDIN G DISC Adolf Ditting and Walter Engi, Zurich, Switzerland; said Engi assignor to said Ditting Application November 8, 1954, Serial No. 467,477

Ciaims priority, application Switzerland November 13, 1953 1 Claim. (Cl. 241-259) The present invention relates to a device for the `adjustment of grinding discs in coiee and spice grinders. In such grinders, accurate adjustment of the grinding discs to ensure the desired grinding fmeness is of particular importance. Since the grinding discs will wear away, it must be possible to readjust them in order to reproduce the desired grinding tineness. The present invention has for its object to fulfill this requirement by simple means.

This invention is characterized by the fact that the displaceable grinding disc is mounted on a shaft arranged so as to be rotatable but axially undisplaceable in a bushing which in turn is axially displaceable but not rotatable in the grinder housing and equipped with a iine thread on which a stop ring formed as a gear and ring nut is arranged, which is forced against a surface `of the housing -by means of a pressure spring, and that a gear mounted on an axially displaceable shaft projecting into the grinder housing and rotatable by means of a handle, meshes with the teeth of the stop ring so that rotation of the handle permits the grinding neness to be adjusted while retraction and rotation of the shaft permits the tooth engagement to be altered.

An embodiment of the invention is shown in the enclosed drawings, in which:

Fig. l is a vertical section of the grinder, and

Fig. 2 is a section along Vline I-l in Fig. 1.

The grinder is provided with a base 1 to which the grinder housing 2 is attached by means of screws 1a.

'The axle 3 forming the motor shaft on which is mounted the grinding disc 4 is axially displaceable in ball bearings 5 and 6 mounted in the guide bushing 7 and base 1 respectively. The guide bushing 7 is displaceably arranged in the housing 2 and secured against rotation by Wedge 8. The lower portion of this guide bushing is equipped with a tine thread 7a onto which a ring 9 is screwed.

circlip 12 secures a disc 13 to the guide bushing 7, and

springs 14 supported in the housing 2 act on the disc 13 so as to force the guide bushing 7 upwards so that ring 9 engages the housing surface 2a. The ring 9 limits the extreme raised position of the grinding disc 4, which gives against the action of the springs 14 if, by way of example, hard particles appear between the grinding discs, The teeth 10 of ring 9 `are engaged by a cup-wheel type gear 16 on shaft 17, which projects into the housing 2 and is supported at 2b and 2c. A knob 18 is mounted at the upper end of the shaft 17, and the said knob is equipped with a scale 19. The shaft 17 is depressed by means of pressure spring 20 so that the wheel 16 permanently meshes with the teeth of ring 9. Rotation of the knob 18 turns ring 9 forward and backward on the guide bushing 7 thereby setting the distance between the rotary grinding disc 4 and the stationary grinding disc 22. As shown in Fig. 2, a rib 2e is `arranged in the housing portion 2c, While Ia pin 17a is inserted in the shaft 17 so that the shaft is free to perform about one revolution only, which determines the maximum distance between the grinding discs.

rIf the two grinding discs are worn so that the finest grinding distance is not obtained at the O position of rotating knob 18, the shaft 17 is retracted against the action of spring 20. The gear 16 is disengaged and by turning the engagement can be altered so that the original grinding neness can again be set by rotating the knob 18.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is:

In a coiee Iand spice grinder, a housing, a bearing iirmly mounted within said housing, a grinding disc rmly mounted in said housing, a rotary shaft carried by said bearing, another grinding disc carried by said shaft and cooperating with the yfirst-mentioned grinding disc, a guide bushing displaceably mounted in said housing for guiding said shaft means securing said guide bushing against rotation, lsaid guide bushing having .a threaded portion, an annular gear carried by said threaded portion, a spring pressing against said guide bushing, another gear meshing with the first-mentioned gear, an axially displaceable shaft carrying said other gear, and a handle carried by the last-mentioned gear.

References Cited in the tile of this patent UNITED STATES PATENTS 2,147,821 Morehouse Feb. 2l, 1939 FOREIGN PATENTS 237,180 Switzerland Aug. 1, 1945 

